The present invention relates to a diving face mask a diver puts on his or her face during diving such as skindiving or scuba-diving, and more particularly to such a diving face mask provided with a purge valve through which a quantity of water accumulating within the mask is purged together with exhalation through the nose of the diver out of the mask.
Conventional diving face masks provided with a purge valve generally characterized by a cylindrical or square tubular section extending forwards from the central zone of a mask's front side to form a valve chamber in which the valve is mounted. For example, Japanese Utility Model Application Laid-Open No. 1974-148700 and U.S. Pat. No. 4,856,120 disclose a single-lens diving face masks provided with a purge valves. These masks of prior art include behind a purge valve, a valve chamber and nose pinching portions formed by partially recessing a main frame of the mask on both sides of the chamber.
Such masks of prior art as have been mentioned above are inconvenient in that a valve chamber extending forwards may obstruct wearer's sight. For example, when a wearer turns his or her eyes obliquely downwards, the valve chamber obstructs his or her sight. With an arrangement that a mask is provided with nose pinching portions immediately behind the valve, the valve and the valve chamber obstruct an easy operation for nose pinching. In other words, the presence of the valve chamber makes it difficult to assure a space allowing the nose pinching portions to be large enough to be easily operated. In spite of these problems, there is a serious demand from many of divers that a two-lens mask also could be provided with such a purge valve in view of significantly advantageous effect the purge valve should present. Nevertheless, no technique available for such a demand has been developed.
Accordingly, it is a principal object of the invention to solve such technical problems as mentioned above and thereby to meet the demand from divers by providing a purge valve at a predetermined location in a zone extending from a top to transversely opposite sides of a main frame of a mask and tubular water purge channels inside the main frame so that the purge valve fluid-communicate with water purge channels.